Nigeria's army on Sunday said it has launched a probe into recent attacks by Boko Haram militants which claimed dozens of lives of lives near Maiduguri, capital of northeast Borno state.

At least 85 people died when insurgents stormed and torched a village on January 30, the third attack in four days defying President Muhammadu Buhari's claim Nigeria had largely defeated the jihadist group.

"The recent unfortunate attacks by Boko Haram terrorists on communities close to Maiduguri, despite our successes, call for concern," the army said.

"The Nigerian Army has already commenced investigation into the attacks...All cases of indiscipline and related acts of misconduct including human rights abuse in the operations will be tried by the Special Court Martial," said the statement said, without clarifying what the probe was investigating.

Thousands of people have fled their homes near Maiduguri for the capital and many are afraid to return, despite government assurances of their safety, after the recent attacks.

Buhari in December claimed that Nigeria had largely won the fight against Boko Haram, but since then the militants have killed dozens in raids and suicide attacks, including across the border in Cameroon.

Rights group Amnesty International has also accused the military itself of committing war crimes and possible crimes against humanity in the course of its operations against the group.

Boko Haram, which seeks a hardline Islamic state in northern Nigeria, has killed some 17,000 people and forced more than 2.6 million others to flee their homes since the start of its insurgency in 2009.